The present invention relates to an improvement of the general type of pipe hanger that is disclosed by U.S. Pat. No. 3,517,901, granted July 30, 1970, to John C. Jenkins, known as a side-load type hanger.
As an inspection of U.S. Pat. No. 3,517,901 will show, the side-load type hanger is characterized by a generally C-shaped saddle in which a pipe section is received. The saddle is welded to one end of a support leg. The support leg is at its other end connected to a support structure. The pipe section, surrounded by a liner, is positioned within the interior of the saddle. In accordance with the teachings of U.S. Pat. No. 3,517,901, a key is inserted through aligned slot-type openings in arm portions of the saddle. The key has a head at its lower end which abuts against the lower arm portion of the saddle. When the key is in place, an installation tool is used to curl the opposite end portion of the key over the end of the upper end portion of saddle.
The use of a key closure for the saddle has produced several problems. Firstly, when the end of the key is bent over the end of the upper arm of the saddle, the weld connection between the saddle and the support leg is stressed and often tore. It is difficult to regulate the clamping force on the pipe, so quite often the clamping force is not tight enough. It is difficult to correct this situation by again grasping the end of the key and curling an additional amount for tightening the grip on the pipe.
Another known form of pipe hanger comprises two pipe engaging members. The central portion of one of the members is secured to an end of the support leg to form a "T". This member is configured to fit down on top of a section of pipe. The second member extends below this section of pipe. A bolt is provided on each side of the pipe. The bolts extend through end portions of the clamp members and thread into the nuts. The bolts are screwed onto the nuts for the purpose of securing the two clamp members together and for regulating the clamping force on the pipe. A system of this type is illustrated in my aforementioned application Ser. No. 730,285.
The above two-bolt type system was in use long before the system disclosed by U.S. Pat. No. 3,517,901. The system disclosed by U.S. Pat. No. 3,517,901 was considered to be an economic improvement over the two-bolt system because it required installation of but a single closure member and a single tool. The "T" support required the use of two bolts. Another objection to this type of nut and bolt system is that there is sometimes improper alignment between the holes of the two members and this creates an assembly problem.
A primary object of the present invention is to provide a side-load type pipe hanger which includes a nut and bolt assembly for closing the open side of the saddle, and which involves an arrangement which allows the bolt to be quickly installed and quickly secured in place by use of a single wrench.
A second primary object of the present invention is to provide a pipe hanger which includes a saddle, and a support leg for the saddle which is constructed to withstand substantial shock loads.
Hanger systems known in the patent literature are disclosed by the following U.S. Pat. Nos. 1,031,851, granted July 9, 1912, to H. C. January; 1,579,418, granted Apr. 6, 1926, to C. C. Tomkinson; 1,619,768, granted Mar. 1, 1927, to Friedrich W. Schubert; 1,850,275, granted Mar. 22, 1932, to Luther R. Zifferer; 2,762,592, granted Sept. 11, 1956, to Charles Adams, Jr.; 2,762,598, granted Sept. 11, 1956, to Richard M. Runge; 2,846,169, granted Aug. 5, 1958, to J. J. Sullivan; 2,936,992, granted May 17, 1960, to George J. Picha et al.; 3,034,753, granted May 15, 1962, to Frank C. Johnston et al.; 3,265,340, granted Aug. 9, 1966, to James W. Attwood; 3,273,838, granted Sept. 20, 1966, to Walter H. Fletcher et al.; 3,506,227, granted Apr. 14, 1970, to John C. Jenkins; 3,517,901, granted June 30, 1970, to J. C. Jenkins; 4,305,557, granted Dec. 15, 1981, to Joseph W. Kowalski; 4,461,440, granted July 24, 1984, to Richard W. Heath; Holland Pat. No. 13267, published in 1925; British Pat. No. 488,960, granted July 18, 1938; and Swedish Pat. No. 152,388, granted Nov. 15, 1955. These patents should be carefully considered for the purpose of putting the present invention into proper perspective relative to the prior art.
The disclosed subject matter of my co-pending application Ser. No. 730,285 is prior art with respect to this application for the reason that such subject matter was put on sale in the summer of 1985.